I frigging hate whenever someone on my twitter timeline, or on some page pastes a FB link to a news and i get 'Nope, you gotta have facebook to see this'... Well, then **** you.Another good example of why we have to deal with certain stuff nowadays....

There are lots of reasons. I imagine a big one is that Steam provides a set of features -- Steamworks -- for free to developers, and those features are pretty valuable.

For instance, Steamworks has a complete system for doing multiplayer authentication and matchmaking. All stuff devs don't have to waste time reinventing, for free. Even things like Steam's bread and butter, content delivery, are valuable; the Bioshock Infinite devs were using Steam to distribute builds internally and to press, AMD/NVidia, etc.

I blame laziness and publishers. I do not want to switch between DVDs when playing different games on PC. I just hope there was less commercial solution than steam that each and every game publisher would use.